A sample identification/sorting apparatus (high-speed droplet charging-type cell sorter) has been proposed which makes a liquid having a sample (minute object), such as a cell, dispersed therein flow through a capillary tube and irradiates light from a light source to a liquid flow to measure the optical information (scattered light and fluorescent information) of the sample in the liquid flow, thereby identifying the sample (for example, see Non-patent Document 1). In the related art, after the sample is identified, a dispensing unit applies ultrasonic vibration to the liquid including a target sample to form droplets and a charge of, for example, several tens of volts is applied to the droplets. Then, several thousands of volts are applied from a polarizing plate to the droplets to divide the drop positions of the droplets into the positive electrode side and the negative electrode side, thereby dispensing the droplet to an arbitrary container (well) of the dispensing unit.
As such, in the high-speed droplet charging-type cell sorter according to the related art using ultrasonic waves, high voltage, and high water pressure, in the sorting process, since the target sample flies from the leading end of the nozzle to an arbitrary well of the plate by droplet charging. Therefore, there is a concern that a large physical damage (stress) will be applied to a living cell. In order to solve this problem, a sample dispensing/identification apparatus shown in FIG. 5, which is a cell sorter of a non-droplet cell sorting type, has been known (for example, see Patent Document 1). In the related art, the leading end of the nozzle is inserted into an arbitrary cell of the plate and the target sample is dispensed, thereby sorting the target sample, without changing a liquid including the target sample into droplets.
A sample dispensing/identification apparatus 100 includes a sample storage portion 101 that stores a sample dispersed in a liquid, a flow cell 102 having a flow path through which the liquid flows, a sorting nozzle 103, a collection container 104, an optical information measuring unit 105 that measures the optical information of the sample, and a tube 106 that introduces the liquid from the sample storage portion 101 to the flow cell 102.